In a wireless communication network, local resources such as air interface resources are highly limited, and congestion is easy to occur. Therefore, it is necessary to put forward an effective method to solve a problem of local congestion.
An ECN (Explicit Congestion Notification, explicit congestion notification) mechanism is available in the prior art for overcoming the problem of congestion. The working procedure of the ECN mechanism is: A sender (or referred to as a local terminal) negotiates an ECN capability with a receiver (or referred to as a remote terminal), and then the sender sends a data packet. After receiving the data packet, a network node sets ECT (ECN Capable Transport, ECN capable transport) as “experiencing congestion” if it is experiencing congestion, and then forwards the set data packet. Finally, after the receiver receives the data packet, if the ECT is “experiencing congestion”, the receiver sets a flag bit ECE (ECN Echo, ECN echo), notifying the sender that it has received the data packet of “experiencing congestion”. After receiving this data packet, the sender sets a flag bit CWR (Congestion Window Reduce, congestion window reduced), notifying the receiver that it has reduced a congestion window.
The existing ECN mechanism is an end-to-end congestion notification mechanism, which strongly depends on support of the network node and the remote terminal for an ECN function. If the existing end-to-end ECN mechanism is used to solve a problem of air interface congestion, once the network node or remote terminal does not support the ECN mechanism, the ECN flag may be discarded, or even the whole IP packet may be discarded, which causes failure of the ECN mechanism and therefore the problem of local congestion cannot be solved.